P3D Re: panorama stereo, Re: stereo to vectograph?

[abram klooswyk <abram.klooswyk@xxxxxx>]

As a sequel to my posting in P3d 2965, 11 Sep 1998:

I found back the reference to L.E.W. van Albada (1868-1955). He was a 
General in the Dutch army (which never was engaged in battle from 1832
to 1940), and a stereo expert. He was famous in designing optics 
(van Albada viewfinder and wide angle oculars).
In 1901 (still a luitenant) he wrote two articles on "Een
Panorama-stereoscoop" in the Dutch "Geillustreerd Weekblad voor 
Fotografie" (they found it necessary to say a photography weekly was
illustrated).

Van Albada claimed to be to first to present a panorama stereoscope.
In fact he designed 3 types.

In the first one he used a modification of "the ordinary stereoscoop",
obviously a Brewster or Holmes type. The schematic illustration shows
a Holmes lens pane with the prismatic lenses rotated over 90 degrees,
left base down, right base up, rotation about the optical centres.
The description says it can be used for panoramic views 6 cm high
(over-under), the right hand view is shifted 6.5 cm to the right.
Van Albada gives a detailed description of the picture taking, for 
360 degrees he recommands 8 views of 45 degrees, preferable mounted on 
glass, as diapositives.

In the second type panorama stereoscope he uses normal lenses, 
a 45 degrees mirror behind the right one (reflecting upwards),
positioning the right hand panoramic slide horizontally.
The third type is complicated, left and right hand panoramic views
are on endless loops rolling over vertical axes.

The first type with the prismatic lenses resembles the handheld prism
viewers now available, only the lens effect restricts it to a limited
viewing distance. On the other hand, it doesn't have the colour
dispersion which the simple prisms have to some extent (but not very
noticeable in my opinion).

Abram Klooswyk


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End of PHOTO-3D Digest 2969
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